A Cochrane review «»1 «Lopez LM, Steiner MJ, Grimes DA, Schulz KF. Strate...»1 included 7 studies with a total of 4 526 subjects. Two trials provided multiple sessions for participants. Five trials provided one session and focused on testing educational material or media. In one study, knowledge gain favored a slide-and-sound presentation compared with a physician's oral presentation (WMD -19.00; 95% CI -27.52 to -10.48, n=100). In another study (n=461), a table with effectiveness categories led to more correct answers than one based on numbers [ORs were 2.42 (95% CI 1.43 to 4.12) and 2.19 (95% CI 1.21 to 3.97)] or a table with categories and numbers [ORs were 2.58 (95% CI 1.5 to 4.42) and 2.03 (95% CI 1.13 to 3.64)]. One trial examined contraceptive choice: women in the expanded program were more likely to choose sterilization (OR 4.26; 95% CI 2.46 to 7.37) or use a modern contraceptive method (OR 2.35; 95% CI 1.82 to 3.03). No trial had an explicit theoretical base, but each used concepts from common theories or models.
Comment: The quality of evidence is downgraded by study quality (several limitations), by indirectness (differences in studied interventions and outcomes), by imprecise results (limited study size for each comparison).